115hp Evinrude dies at 1/2 throttle

[matt194]

My motor runs good at full throttle for the first run around the lake (aprox. 10 minutes), then I go back to the marina and park it for a minute and when I go back out my motor dies when I try to go past half throttle. This has happened the last couple of times I went out there. Could it be my power packs overheating? Any other ideas?

 

[tashasdaddy]

Re: 115hp Evinrude dies at 1/2 throttle

when it does this, check you spark on all 4. it could be a coil failing, or a power pack. if you don't have spark on one. completely swap it with a coil that does have spark. if the problem follows the coil, replace the coil. depend on the year of your motor you have 2 power packs. if you have 2 cylinders not firing, swap the power packs, positions.

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

ok I will try that out. Thanks

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

I was thinking about what you said and I don't think it would work because the motor will run good at low speed, so wouldn't I still get a spark when I went back to the dock to test for spark? I have cleaned out the carbs so clogged jets isn't the problem. How could I find out if its the needle sticking or the float not properly aligned?

 

[tashasdaddy]

Re: 115hp Evinrude dies at 1/2 throttle

you stop on the water hook up a spark tester right there. you can return to dock to swap coils, then take the boat back out, let it warm up again, and see if it act up.

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

So you want me to hook up a spark tester then try to go at full throttle and check for spark while moving? Do you think once the engine is heated up I'm only running on 2 or 3 cylinders throughout the entire throttle range?

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

Do you think I could heat up the power packs and coils in my driveway and check for spark or do I have to run the engine at the lake to heat it up?

 

[iwombat]

Re: 115hp Evinrude dies at 1/2 throttle

Break out a hairdryer and heat 'em up in the driveway.

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

How long should it take for the power pack to fail if it is bad? I don't want to damage the power pack by holding the blow dryer on the power pack for to long.

 

[iwombat]

Re: 115hp Evinrude dies at 1/2 throttle

I don't think you CAN hurt the powerpack with the hair dryer, unless maybe it's a yak hair dryer.

In the past it's taken a good 5 minute heating to make stuff fail for me.

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

ok thanks

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

Well I did the test and the motor never dropped in rpms. What should I test next?

 

[CharlieB]

Re: 115hp Evinrude dies at 1/2 throttle

An inductive tach used on-the-water could show a cyl dropping out once at temp.

A stator could cause on side to fail once at temp, testing at temp could be a trick. Use a DVA meter and carefully tap into the plug connecting the stator to the module and see if running high speed output begins to fall off with temp.

Then repeat on other side.

Otherwise remove the stator and ohms test at room temp then heat to 150 - 180 in the oven and retest ohms.

 

[tashasdaddy]

Re: 115hp Evinrude dies at 1/2 throttle

if the coil or power pack is failing because of heat, it will show up at idle. you have to get the motor running a while. sometines take 20 minutes. i do not believe in the blow dryer test.

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

So you said if its heat related it will show up at idle. My engine seems to run good at idle. Would my engine still seem to run good at idle even if I lost a cylinder?

 

[matt194]

Re: 115hp Evinrude dies at 1/2 throttle

I did all the test in the manual for the ignition system. The only part that did not test out correctly was the sensor coil. On the port side I got the correct reading of between 30 and 50 ohms. One the starboard side I got readings of infinity. Could this be causing my problem? Do you think there is something disconnected since it gave me a reading of infinity?